Offshore Solar Power to Float Using Recycled Carbon Fiber Instead of Styrofoam Causing 'Microplastic' Pollution

Sanggiyeon-Hanyang University Research Team Develops Processing Technology
Lasts Longer Than Styrofoam and Eliminates Microplastic Issues

A joint research team from the Korea Institute of Industrial Technology and Hanyang University demonstrating a full-scale prototype of a marine buoyancy body made by recycling low-quality carbon fiber, along with a simplified verification test in a water tank.

[Asia Economy Reporter Kim Bong-su] Domestic researchers have developed a technology to recycle discarded carbon fiber waste into durable offshore solar power buoyancy bodies that do not cause microplastic pollution like Styrofoam.

The Korea Institute of Industrial Technology (KITECH), in collaboration with Hanyang University, announced on the 13th that they have developed a technology to manufacture affordable and highly durable offshore solar power buoyancy bodies by recycling low-quality carbon fibers that are either unsellable or scheduled for disposal.

Solar power generation produces electricity using sunlight, so it does not incur fuel costs or cause air pollution, making it a representative renewable energy source. However, in South Korea, where idle flat land is scarce and installations are mainly on mountainous areas, concerns have been raised about damage to forest resources and landscapes.

As an alternative, offshore solar power generation, which installs power facilities on water surfaces using buoyancy bodies such as Styrofoam that float well, has recently gained attention. Offshore solar power generation causes less environmental damage, has higher power generation efficiency than land facilities due to the cooling effect of water temperature, and is advantageous for securing space because South Korea is surrounded by the sea on three sides, providing abundant idle water surfaces. However, harsh marine environments such as strong waves, wind, and corrosive saltwater result in high maintenance costs for buoyancy bodies, and Styrofoam buoyancy bodies release microplastics, which is a disadvantage.

The joint research team led by Dr. Kim Kwang-seok of KITECH’s Carbon Lightweight Materials Application Research Group and Professor Choi Jun-myung of Hanyang University focused on "carbon fiber composites" as a new material for offshore buoyancy bodies. They embarked on developing an upcycling technology to recycle low-quality carbon fibers that are discarded or sold cheaply.

The research team used carbon fibers as composite materials added to ceramics, metals, and plastic resins. The surface of carbon fibers consists of a graphite structure where carbon atoms are arranged in a hexagonal pattern, making it stable. However, to increase the adhesion strength between carbon fibers and plastic resin during composite manufacturing, a separate carbon fiber surface treatment process is required. This process uses mild acids such as hydrochloric acid and sulfuric acid, which generate toxic byproducts, and residual acid on the carbon fibers creates weak adhesion layers that degrade mechanical properties.

During experiments combining carbon nanotubes and metal particles, the research team accidentally discovered that exposing the carbon fiber surface to a short but intense light energy, like a camera flash, maximizes the surface bonding strength between carbon fibers and plastic resin. This light energy is a pulse-type energy source mainly used in printed electronics technology, and when applied to carbon fibers, it enables effective functionalization with a fast and simple process, enhancing surface bonding strength.

To elucidate the principle, the research team used molecular dynamics simulations and confirmed that oxygen-containing functional groups are formed on the carbon fiber surface exposed to light, inducing physical and chemical interlocking effects at the nanoscale that strengthen bonding. Carbon fibers treated with this method showed significantly improved mechanical properties and durability, achieving about 95% of the performance of commercial-grade A-class carbon fibers.

Based on this discovery, the research team began producing offshore buoyancy body prototypes, completed preliminary verification in seawater tanks, and is currently conducting field verification in the inner sea of the Saemangeum Seawall in Jeollabuk-do. The produced offshore buoyancy body prototypes feature optimized upper and lower structures that completely block seawater inflow. The carbon fiber composite outer shell fully encloses the internal foam plastic filler to suppress microplastic emissions and is designed and manufactured to be safe against external impacts. Notably, it can be manufactured at over 20% lower cost compared to offshore buoyancy bodies using A-class carbon fibers, while meeting all characteristics such as weather resistance and saltwater resistance.

In the verification phase, one set consists of nine offshore buoyancy bodies supporting 27 solar panels of 450W or more. This structure can withstand 2-meter-high waves and has the stability to be used in actual marine environments for 20 years.

Dr. Kim Kwang-seok stated, “Offshore buoyancy bodies using low-quality carbon fibers can be reused by enhancing quality with the same technology even after their service life ends,” adding, “We plan to focus on developing and commercializing equipment capable of large-scale carbon fiber surface treatment in the future.”

The research results were published last month in the international journal for life, physical, and environmental sciences, iScience (IF 6.107).

This content was produced with the assistance of AI translation services.